The capital stack is the blueprint of every private equity acquisition. According to Icon Business Advisors, a typical $12 million lower-middle-market acquisition is built with roughly $7 million in senior bank debt, $1.5 million in mezzanine or subordinated debt, $1.5 million in seller financing, and $2 million in buyer equity. The ratios shift by deal size and buyer type. The structure is consistent.
TL;DR: Lower-middle-market PE acquisitions layer senior debt, mezzanine, seller notes, and fund equity into a stacked capital structure. Debt covers 50-65% of enterprise value. PE equity covers 20-30%. The deal structure, whether asset or stock, determines tax outcome and liability exposure for both sides.
If you are a business owner evaluating a PE offer, this is the architecture behind the number on the term sheet. If you are an operator or LP trying to understand how these deals generate returns, the stack explains everything.
The four layers of an LMM acquisition
Every lower-middle-market private equity transaction is built on the same capital stack. Four components. Different cost. Different risk. Different repayment priority.
Senior debt
First in, cheapest, most secured. Senior lenders advance 2.5-4x EBITDA on a quality lower-middle-market business. The rate floats at SOFR plus 3-5%. Senior lenders hold a first lien on company assets and get paid before anyone else if the deal unwinds.
Lenders evaluate four factors: EBITDA consistency, revenue predictability, customer concentration, and management depth. A business with 80% or more recurring revenue secures more leverage. A business where three customers drive 60% of revenue gets less. That difference feeds directly into the purchase price a buyer can offer. Every improvement in EBITDA quality is both a valuation story and a financing story.
Mezzanine debt
Mezzanine sits behind senior debt in the repayment priority. It costs more, typically 10-14% cash interest plus a PIK component or equity kicker, because it takes more risk. Not every LMM deal uses it. Mezzanine appears more often in the $50 million to $150 million enterprise value range, where senior debt alone cannot cover the financing gap. In deals below $20 million in enterprise value, buyers generally move directly from senior debt to equity.
Seller financing
The seller carries a portion of the purchase price as a subordinated note. Terms typically run 5-7 years at 5-8% interest. The seller note sits behind all bank debt in the repayment waterfall. It is common in SBA transactions and in deals where the buyer needs to bridge a valuation gap.
One critical detail: under SBA regulations effective June 2025, seller notes can count toward the buyer's required 10% equity injection only if the note is on full standby, meaning no principal or interest payments for the entire loan term. Most sellers find those terms unacceptable. Understand where the note sits before agreeing to carry paper.
PE fund equity
The residual. After debt and any seller note, the PE fund writes an equity check covering the balance. For PE buyers, equity typically represents 30-50% of enterprise value. Equity earns the highest potential return and absorbs losses first. The fund's return model depends on leverage. The more debt accessible, the smaller the equity check and the higher the percentage return on invested capital.
Asset purchase versus stock purchase
The second structural decision is how the transaction is legally organized: asset purchase, stock purchase, or merger. Asset purchases are the most common structure in lower-middle-market acquisitions.
In an asset purchase, the buyer acquires specific assets and liabilities, leaving behind what they do not want. Assets receive a stepped-up tax basis, which creates depreciation deductions post-close. The buyer also isolates itself from undisclosed liabilities attached to the selling entity.
In a stock purchase, ownership of the entity transfers directly. The seller gets a cleaner transaction with capital gains treatment on most proceeds. The buyer assumes all liabilities, known and unknown, which is why representations and warranties are negotiated more heavily in stock deals. PE buyers generally prefer asset purchases. Sellers often push back because of the tax consequences of an asset sale.
When both sides cannot agree, a 338(h)(10) election can bridge the gap. The transaction is structured as a stock purchase for legal purposes but treated as an asset purchase for tax purposes. It requires mutual consent and applies primarily to S-corporation targets.
Closing mechanics: what the term sheet does not show
Purchase price adjustments
Ninety-two percent of lower-middle-market deals include a purchase price adjustment mechanism, according to SRS Acquiom's LMM Deals Report. A PPA sets a target working capital level at close. If actual working capital falls below the target, the seller owes the buyer the shortfall. If it exceeds the target, the buyer pays up.
PPAs are not optional fine print. They settle the difference between what the letter of intent says and what you actually receive at the closing table. Nearly half of LMM deals also include a separate PPA escrow averaging 1.23% of transaction value.
Earnouts
More than a third of lower-middle-market deals include an earnout. The seller receives a portion of the purchase price contingent on post-close business performance, typically measured over 24 months. For deals under $25 million, the earnout as a percentage of closing consideration is roughly double that of deals twice the size.
Earnouts protect the buyer against paying for growth that does not materialize. They create risk for the seller. If you are operating the business post-close under a PE owner making resource and strategy decisions, your ability to control earnout achievement depends heavily on the management autonomy provisions negotiated into the agreement. See how earnout structures work in practice before agreeing to one.
Escrows
The general indemnification escrow in LMM deals runs to a median of 12.5% of transaction value. That amount is held from closing proceeds and released after the survival period, subject to any claims. Add a separate PPA escrow and any special escrows for known issues and sellers routinely have 15-20% of total proceeds in limbo for 12-18 months post-close.
Representations and warranties insurance can reduce escrow requirements. It appears in fewer than one-third of LMM deals versus 40% of all transactions. The premium cost and deal-size economics make it less practical below $20 million in enterprise value.
Financing contingency
If the buyer includes a financing contingency in the LOI, they can walk from the deal if their lender declines. That is a free option at the seller's expense. Sophisticated sellers push for one of three alternatives: no financing contingency, a defined financing period with an expiration date, or a reverse break fee, typically 2-5% of enterprise value, payable if the buyer fails to close due to financing failure.
A reverse break fee of 3% on a $25 million transaction is $750,000. That is real compensation for the disruption and opportunity cost of a failed process. PE buyers generally resist reverse break fees. Sellers with competitive processes have more leverage to demand them.
Four questions to ask before you sign
Private equity deal structure determines more than the purchase price. It determines how quickly you close, how much you receive at the table, how much risk you carry post-close, and whether you can hold the buyer accountable if they walk.
Ask any PE buyer these four questions before signing anything:
- Is your debt financing committed, or are you still in discussions with lenders?
- What is the total leverage ratio — total debt divided by EBITDA?
- Is this structured as an asset purchase or a stock purchase, and what are the tax consequences for me?
- Does the LOI include a financing contingency, and will you accept a reverse break fee?
Committed financing, clean deal structure, and a buyer willing to put capital at risk on a break fee all signal a buyer who is serious about closing. Vague answers to any of these questions are information worth acting on.
PGC structures every acquisition with this framework built in from day one. The deal structure is not a back-office detail. It is where the operator decides whether to trust the buyer or keep looking.
Frequently Asked Questions
What is the typical capital stack for a lower-middle-market PE acquisition?
Most lower-middle-market PE acquisitions use 50-65% debt (senior secured plus any mezzanine), 10-20% seller financing, and 20-30% PE fund equity. Senior lenders typically advance 2.5-4x EBITDA. The exact mix depends on EBITDA quality, deal size, and lender appetite at the time of the transaction.
What is the difference between an asset purchase and a stock purchase in PE deals?
An asset purchase lets the buyer acquire specific assets and liabilities with a stepped-up tax basis. A stock purchase transfers the entire entity, including all liabilities. Sellers generally prefer stock purchases for tax simplicity. Buyers prefer asset purchases to isolate unknown liabilities. A 338(h)(10) election allows a stock deal to be treated as an asset purchase for tax purposes when both sides agree.
Should a seller accept a seller note in a PE transaction?
A seller note is subordinated to all senior bank debt. In SBA transactions under current rules, the note may need to be on full standby for the entire loan term. Sellers must understand their position in the repayment waterfall before accepting. A note under 15% of total consideration with a creditworthy buyer is manageable. A note above 30% with a first-time buyer carries meaningful risk.
What is a purchase price adjustment and why does it matter at close?
A PPA reconciles actual working capital at close against a target level agreed in the purchase agreement. If working capital comes in below target, the seller pays the buyer the shortfall. If it exceeds the target, the buyer pays the seller. About 92% of lower-middle-market deals include a PPA. Sellers must understand the working capital methodology and the target level before signing any LOI.
